You would do 0.25x (x is the unknown total number)=19. It is because of is a multiply sign, so 0.25*x=19. Divide both sides by 0.25 and you get 76 as your answer.
P(A) = P(8) + P(9) + P(10) = 3/10 so P(A complement) = 1 - P(A) = 1 - 3/10 = 7/10 - D
Subtract 125,300 from 800,009. From there you find that they made 674,709 in profit.
Answer is 674,709